EP3189954A1 - Bracelet and method for manufacturing thereof - Google Patents

Abstract

The present invention relates to a method of manufacturing a bracelet (4) watch (3) or jewelry comprising the steps of: - Provision of a first synthetic material, - providing an extrusion line (1) with a die (2) for producing an extrudate (6) from the first material, characterized in that it further comprises one or more of the following steps: - providing one or more additional materials distinguished from the first material by their color and / or properties, - Provision of a die (2) having a particular profile selected from a circular profile, an oval profile, a curved profile and a profile with projecting areas (5).

Description

OBJECT OF THE INVENTION

The present invention relates to the field of watchmaking and jewelery. More particularly, it relates to an extrusion process or co-extrusion to make bracelets or costume jewelry and bracelets or jewelry fantasy obtained by this method.

TECHNOLOGICAL BACKGROUND AND STATE OF THE ART

Today, watchbands or fancy plastic jewelery are essentially manufactured by injection molding or compression molding. These processes allow the rapid manufacture of large series of this type of plastic objects with complex shapes. However, they have the disadvantage of requiring expensive tools, all the more expensive as the object is complex. In addition, if it is desired to obtain bracelets or costume jewelry with different colors or materials in the mass, it is necessary to use several stages of overmoulding or bi-injection. Subsequently, we will speak only of watchbands, but only as an example and without limitation to other objects portable or not achievable with this technique.

In the past, it has been proposed to make watchbands by an extrusion process, which is a less expensive method. Thus, the document FR 2,121,864 discloses a method of making a tape plastic having at the lateral ends cylindrical channels for receiving the support rods of the watch case.

The manufacture of bracelets by extrusion was limited to the manufacture of simple form of bracelets, unicolor and made of the same material. But bracelets with a relief, different colors or a particular touch are very popular with customers. In addition to the aesthetic aspects, it may also be interesting to integrate various materials within the bracelet to change the functional properties of the bracelet, such as increase the rigidity at specific locations of the bracelet, which are more mechanically stressed. It is also possible to achieve a surface with a pleasant touch, and a comfortable lower part, for example limiting perspiration, to be in permanent contact with the skin.

SUMMARY OF THE INVENTION

The object of the present invention is to produce bracelets presenting original geometries and patterns by means of a simple and inexpensive method. The present invention also aims to provide bracelets with variable functional properties, such as for example with reinforcements located in certain specific places.

For this purpose, a manufacturing method according to the appended claim 1 is proposed and particular embodiments are included in the dependent claims.

BRIEF DESCRIPTION OF THE FIGURES

• La figure 1 représente une vue schématique d'une ligne d'extrusion connue en soi.
• Les figures 2a et 2b représentent une vue en perspective de bracelets fabriqués avec le procédé d'extrusion selon l'invention. Les bracelets selon ce mode de réalisation forment respectivement un tube à la figure 2a et une bande bombée à la figure 2b.
• Les figures 3 et 4 représentent des vues en perspective de montres avec un bracelet fabriqué selon le procédé d'extrusion de l'invention. Les bracelets présentent des zones en relief séparées par des creusures.
• La figure 5 représente une vue schématique de deux extrudats issus de la filière. Selon l'invention, le bracelet est extrudé dans le sens transversal du bracelet. La figure 6 représente une vue en perspective de ces mêmes extrudats avec à une ou à chaque extrémité latérale une structure tubulaire creuse.
• La figure 7 représente une vue schématique des extrudeuses en amont de la filière de co-extrusion. Les figures 8 et 9 présentent une vue du dessus des bracelets ainsi obtenus avec des rayures transversales et longitudinales respectivement.
• La figure 10 représente une vue en perspective de l'extrudat issu du procédé selon l'invention. Il comporte au niveau de ses extrémités latérales une matière plastique distincte de celle disposée au centre.
• La figure 11 représente une vue partielle en perspective de l'extrudat issu du procédé selon l'invention avec un renfort intégré au niveau des extrémités latérales.
• La figure 12 représente une vue partielle en perspective d'une montre avec un bracelet obtenu selon le procédé de l'invention et fixé au boîtier avec une construction de type NATO.
• La figure 13 représente une vue en perspective d'une montre avec un bracelet obtenu selon le procédé de l'invention, avec fermeture par un système à clous.
• La figure 14 représente un brin du bracelet issu d'un extrudat de la figure 6 après découpe laser ou étampage pour réaliser les trous nécessaires à la fixation sur le boîtier de montre et sur la boucle.
• La figure 15 représente une boîte de montre avec un système de cornes pour accrocher le bracelet.
• La figure 16 représente une boucle de fermeture à fixer au bracelet avec un système de barrette.
• La figure 17 représente une montre avec un bracelet bicolore avec la couleur de la face intérieure différente de la couleur de la face extérieure.
• La figure 18 représente un brin de bracelet noir avec des bandes phosphorescentes obtenu par le procédé de co-extrusion décrit dans l'invention. Une première vue est une vue en coupe longitudinale du brin de bracelet et la seconde vue est une vue du dessus du brin de bracelet.

The features and advantages of the present invention will become apparent on reading the detailed description below with reference to the following figures.

• The figure 1 represents a schematic view of an extrusion line known per se.
• The Figures 2a and 2b represent a perspective view of bracelets made with the extrusion process according to the invention. The bracelets according to this embodiment respectively form a tube at the figure 2a and a domed band at the figure 2b .
• The Figures 3 and 4 represent perspective views of watches with a bracelet manufactured according to the extrusion method of the invention. The bracelets have raised areas separated by hollows.
• The figure 5 represents a schematic view of two extrudates from the die. According to the invention, the bracelet is extruded in the transverse direction of the bracelet. The figure 6 represents a perspective view of these same extrudates with a hollow tubular structure at one or at each lateral end.
• The figure 7 represents a schematic view of the extruders upstream of the coextrusion die. The Figures 8 and 9 have a view from above of the bracelets thus obtained with transverse and longitudinal stripes respectively.
• The figure 10 represents a perspective view of the extrudate resulting from the process according to the invention. It has at its lateral ends a plastic material distinct from that disposed in the center.
• The figure 11 represents a partial perspective view of the extrudate resulting from the process according to the invention with an integrated reinforcement at the lateral ends.
• The figure 12 is a partial perspective view of a watch with a bracelet obtained according to the method of the invention and attached to the housing with a construction of NATO type.
• The figure 13 represents a perspective view of a watch with a bracelet obtained according to the method of the invention, with closure by a stud system.
• The figure 14 represents a strand of the bracelet from an extrudate of the figure 6 after laser cutting or stamping to make the necessary holes for fixing on the watch case and on the buckle.
• The figure 15 represents a watch case with a system of horns to hang the bracelet.
• The figure 16 represents a closure loop to attach to the bracelet with a bar system.
• The figure 17 represents a watch with a two-tone bracelet with the color of the inner face different from the color of the outer face.
• The figure 18 represents a strand of black bracelet with phosphorescent strips obtained by the coextrusion process described in the invention. A first view is a longitudinal sectional view of the bracelet strand and the second view is a top view of the bracelet strand.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to a method of manufacturing wristbands for watches or fantasy jewelry by plastic extrusion.

The method may be to manufacture an extrudate having a width corresponding to the width of the bracelet or to manufacture an extrudate having a width corresponding to the length of one or both strands of the bracelet.

The bracelet obtained with the method according to the invention has the characteristic of presenting an original profile, stripes of colors, including including luminescent stripes, or different properties depending on the position. It can of course have one or more of these characteristics.

The term "original profile" means a bracelet of rounded cross section forming, for example, an oval, a circle or a half-spindle. As an example shown in Figures 1 and 2a the die 2 of the extrusion line 1 is adapted to manufacture a bracelet 4 forming a solid or hollow tube. To the figure 2b is represented a bracelet with a profile forming a half-spindle, ie a curved profile formed of a flat edge surmounted by an edge with a certain radius of curvature. The term "original profile" also refers to a bracelet presenting, on its cross section or on its longitudinal section, three-dimensional patterns formed of zones in relief, which will be described as projecting zones. For example, the bracelet 4 resulting from the process may be formed of protruding longitudinal strips 5 separated by one or more recesses 10 as shown in FIGS. Figures 3 and 4 . Many profiles are imaginable with a symmetrical or non-symmetrical profile with respect to the longitudinal or transverse axis of the bracelet, respectively. The projecting zone or zones may extend longitudinally or transversely depending on whether the extrusion process consists in producing an extrudate of width corresponding to the width of the bracelet or an extrudate of width corresponding to the length of one or both strands. of the bracelet.

To facilitate the subsequent assembly of the bracelet to the watch case, it is advantageous to manufacture an extrudate 6 of width corresponding to the length of a strand with one or each lateral end of the extrudate a hollow tubular structure projecting 7 as represented at Figures 5 and 6 . The hollow tubular structures form through holes 9 intended to respectively receive a bar for hanging on a watch case with horns 14 as shown in FIG. figure 15 and a loop 15 as shown in the figure 16 . It is also conceivable to make an extrudate 6 possessing only one lateral end, a projecting hollow tubular structure 7. In this case, the latter forms a through-hole intended to receive the bar allowing the attachment to the watch case with horns 14 (FIG. figure 15 ). It is also conceivable to make the two strands of the bracelet starting from a single band with a tubular structure at one lateral end and two tubular structures located near the center of the band and subsequently to perform the necessary cuts to obtain both strands.

The original profiles that can be obtained by the extrusion process according to the invention have been described above. Thanks to this process, it is also easy to combine within the bracelet several materials that are distinguished by their colors and / or properties.

Thus, bracelets having in the mass an alternation of strips 16 of different colors can be made by coextrusion ( Figures 7 to 9 ). As previously, the strips 16 may extend longitudinally or transversely depending on whether the extrudate has a width corresponding to the width or the length of the bracelet. Color bands also include luminescent strips extending in the transverse or longitudinal direction. So, the figure 18 illustrates the invention for a bracelet having in the mass three transverse phosphorescent strips 16. The bi-color and bi-material coextruded bracelet was made of thermoplastic polyurethanes (TPU) starting from two extrusion machines joined together, with a common coextrusion head. A first machine is used for feeding the material A and a second machine for feeding the photoluminescent material B. The two thermoplastics are thus conveyed in the die and punch tooling allowing a controlled distribution of the two streams of materials . The distribution of the two raw material flows is given by the tooling, the small dimensional evolutions being modulated with the machine parameters (speed of draw, screw / sleeve temperatures, material flow rate, screw rotation speed, etc ...). It is obviously conceivable to secure a third machine with a new coextrusion head accepting three different power supplies to co-extrude the same type of tri-material bracelet and / or tri-color.

It is also possible to obtain by this coextrusion process, a two-tone bracelet with a color of the top different from the color of the bottom in contact with the skin ( figure 17 ). Substances having different physical characteristics can also be co-extruded to modulate the properties according to the zones of the bracelet. In the case of an extrudate of width corresponding to the length of a strand as shown in FIG. figure 10 it is particularly advantageous to introduce at the lateral ends of the coextrusion die a plastic material having superior mechanical properties because these zones of attachment to the housing and to the loop are particularly mechanically stressed. By way of example, the central material may comprise a thermoplastic with a Shore A hardness of 55 and the lateral ends a thermoplastic with a Shore A hardness of 75. Coextrusion also makes it possible to produce bracelets having a material below. different from the material above. A bracelet with a comfortable lining with a soft touch on the underside and a shiny finish on the top can be obtained. In another example, the bracelet may comprise two co-extruded materials with a first material conferring antibacterial and / or antiperspirant properties to the inner face of the bracelet and a second material imparting a particular aesthetic finish to the outer face of the bracelet.

According to another embodiment, a reinforcement 8 may be integrated during the extrusion to simulate the sewing thread, provide strength and rigidity to the plastic in certain areas, or simply create a decor. The reinforcement can be in the form of cables, tubes, wires springs of carbon or other material of synthetic, natural, metallic or mineral origin. For example, a metal or textile tube 8 may be integrated at the level of one or more hollow tubular structures 7, and this, always, in order to reinforce this fragile part of the bracelet ( figure 11 ).

In another embodiment, the plastics material may be extruded to coat a web, for example, metal. More specifically, the metal strip may be a steel bistable spring strip for making a "Slap Wrap" type bracelet. The extrusion coating of a strip makes it possible to combine the comfort and color appearance of the plastic on the surface with a rigid holding provided by the core band and thus to envisage systems of watchbands without a clasp.

• TPE-O - Oléfines thermoplastiques
• TPE-S - plus particulièrement les composés SBS, SEBS ou SEPS styrénique
• TPE-V - plus particulièrement les composés PP/EPDM vulcanisé ou les composés TPSi-V (combinaison de thermoplastique et de silicone réticulé)
• TPE-E - Composé de copolyester
• TPE-U - Polyuréthane thermoplastique
• TPE-A - Polyamide thermoplastique
• Résines ionomères.

According to the invention, the synthetic materials used during extrusion or c-oextrusion are mixtures comprising at least one thermoplastic polymer. Preferably, the mixture comprises less a thermoplastic elastomer (TPE) chosen from the following list:

• TPE-O - Thermoplastic olefins
• TPE-S - more particularly SBS, SEBS or SEPS styrenic compounds
• TPE-V - more particularly vulcanized PP / EPDM compounds or TPSi-V compounds (combination of thermoplastic and cross-linked silicone)
• TPE-E - copolyester compound
• TPE-U - Thermoplastic Polyurethane
• TPE-A - Thermoplastic polyamide
• Ionomer resins.

Preferably, the selected material has a Shore A hardness between 55 and 75, zones of different hardness can be combined to improve the comfort and ergonomics of the bracelet as already mentioned.

• Exemples de charges pour améliorer le confort :
  • Céramiques type nitrure de bore hexagonal pour évacuer l'énergie calorifique et diminuer la sudation ;
  • Fibres textiles ayant un effet capillaire afin d'évacuer la sueur ;
  • Agents antibactériens comme les particules d'argent ou de pyrithione de zinc ou sels d'aluminium pour un effet anti-odeur ;
• Exemples d'additifs pour créer des effets esthétiques intéressants :
  • Pigments colorés ou colorants, composés ayant des propriétés fluorescentes, phosphorescentes, thermochromiques ou photochromiques ;
• Exemples d'additifs pour améliorer la stabilité dans le temps du bracelet :
  • Additifs anti-UV.

In addition, the material or materials chosen for implementing the method according to the invention may comprise fillers to improve the comfort, the aesthetic appearance and the stability over time of the bracelet:

• Examples of loads to improve comfort:
  • Ceramics type hexagonal boron nitride to evacuate heat energy and reduce sweating;
  • Textile fibers having a capillary effect in order to evacuate sweat;
  • Antibacterial agents such as silver particles or zinc pyrithione or aluminum salts for an anti-odor effect;
• Examples of additives to create interesting aesthetic effects:
  • Colored or coloring pigments, compounds having fluorescent, phosphorescent, thermochromic or photochromic properties;
• Examples of additives to improve the stability over time of the bracelet:
  • UV additives.

These fillers and additives may be added to the feeder hopper of the extruder screw or have been previously integrated into the material. Still in a spirit of modulating the properties within the bracelet, it is obviously possible in the case of co-extrusion to introduce charges and additives in some of the extruded materials.

After manufacture of the bracelet by extrusion, additional cutting steps can be performed to facilitate the attachment of the bracelet to the watch case in the case of a watch application and to integrate the clasp.

In the case of bracelets from the extrusion process in the longitudinal direction of the bracelet, the shape of the bracelet and the desired holes are obtained for example by stamping or laser cutting. The strip obtained after extrusion can be in one piece and attached to the housing of watch using loops 12 arranged on each side of the watch case as shown in FIG. figure 12 ; it is a so-called NATO construction. Alternatively, a short strand and a long strand are cut in the plastic strip to achieve a conventional bracelet. A compression overmolding operation is then necessary to create the inserts, similar to the tubular structures of the figure 6 . It is also conceivable to introduce a nail clasp system 13 which is housed in a hole of the bracelet ( figure 13 ). It is also conceivable to make a bracelet without clasp as for the rigid tubular bracelets of the figure 2a . In this case, the free ends of the strip are fused in particular by a method of ultrasonic fusion, infrared or laser heating.

In the case of bracelets from the extrusion process in the transverse direction of the bracelet, the assembly to the watch case is easier to achieve. By laser cutting or stamping at the tubular structures, the respective hooks 11 for the watch case and for the loop are made as shown in FIG. figure 14 . Other means of fixing the housing and closing as described above are also conceivable.

The bracelets thus made by extrusion have many advantages. The process is simple and inexpensive while ensuring a high production rate. Multicolored bracelets tinted in the mass with clear bands can be obtained unlike the current injection process. All geometries are conceivable. It is furthermore possible to decorate the surface of the bracelet with additional ornaments such as sewing or decor by inkjet printing, pad printing, etc.

Legend

1. (1) Extrusion line
2. (2) Filière
3. (3) Watch
4. (4) Bracelet
5. (5) Projecting areas
6. (6) Extrudate
7. (7) Hollow tubular structure
8. (8) Reinforcement or decoration, for example, in the form of wire, tube, strip.
9. (9) Opening hole for attachment to the watch case and the closing buckle.
10. (10) Cracks
11. (11) Cutting or catching
12. (12) Passing
13. (13) Clasp with nails
14. (14) Horn
15. (15) Loop
16. (16) Color or luminescent strip

Claims (21)

A method of manufacturing a bracelet (4) of a watch (3) or jewel comprising the steps of: - Provision of a first synthetic material, - providing an extrusion line (1) with a die (2) for producing an extrudate (6) from the first material, characterized in that it comprises at least one of the following steps: - providing one or more additional materials distinguished from the first material by their colors and / or properties, - Provision of a die (2) having a particular profile selected from a circular profile, an oval profile, a curved profile and a profile with projecting areas (5). The method of claim 1, wherein the extrudate (6) has a width corresponding to the width of the bracelet (4) or the length of one or two strands of the bracelet (4). The method of claim 1 or 2, wherein one or more of the additional materials is a synthetic material coextruded with the first material. A method according to any one of the preceding claims, wherein one or more of the additional materials is a decoration or reinforcement (8) integrated during extrusion through the die (2). The method of claim 4, wherein the decoration or reinforcement (8) is a wire, a strip or a tube. Method according to claim 4 or 5, wherein the decoration or reinforcement (8) is made of fibers or made of a metallic material. A method according to any one of claims 4 to 6, wherein the reinforcement (8) is integrated at one or both ends side of the die (2) when the extrudate (6) has a width corresponding to the length of one or two strands of the bracelet (4). Method according to any one of claims 4 to 6, wherein the reinforcement (8) is integrated in the core of the die (2) to manufacture a bracelet (4) with a plastic envelope coating the reinforcement (8). Method according to any one of the preceding claims, wherein the die (2) has at one or both lateral ends a hollow tubular profile (7) projecting from the rest of the profile of the die (2). Method according to claim 9, comprising a step of laser cutting or stamping the extrudate (6) from the die (2) to form the hooks (11) respectively to a watch case and to a loop (15) closure. A method according to any one of the preceding claims, wherein the first material and, optionally one or more additional materials, comprises a filler improving the mechanical performance, comfort, stability over time and / or the aesthetic appearance of the bracelet ( 4). The method of claim 11, wherein the filler is selected from the group consisting of ceramic particles, antibacterial agents such as silver particles or zinc pyrithione particles or aluminum salts, textile fibers, anti-UV compounds, pigments, fluorescent compounds, phosphorescent compounds, thermochromic compounds, photochromic compounds and a mixture thereof. Bracelet (4) watch or jewel, or jewel obtained using the method according to any one of the preceding claims. Bracelet or jewel (4) according to claim 13, comprising strips (16) transverse or longitudinal different colors dyed in the mass. Bracelet (4) according to claim 13 or 14, comprising in the mass strips (16) transverse or longitudinal luminescent. Bracelet (4) according to any one of claims 13 to 15, comprising an inner face and an outer face made of different materials. Bracelet (4) according to any one of claims 13 to 16, comprising compounds having antibacterial, anti-odor, anti-sweat, UV protection, phosphorescent, fluorescent, thermochromic and / or photochromic properties. Bracelet (4) according to any one of claims 13 to 17, comprising a reinforcement (8) disposed at one end, at its ends or in the middle of its thickness. Bracelet (4) according to any one of claims 13 to 18, comprising at one or at its ends a plastic material different in its mechanical properties of the plastic material disposed between the ends. Bracelet (4) according to any one of claims 13 to 19, comprising zones of different hardness with a Shore A hardness between 55 and 75. Watch (3) or jewel comprising a bracelet (4) according to any one of claims 13 to 20.

Images